Starter Armando Galarraga is out, and reliever Hector Ambriz is up

The Astros have designated Armando Galarraga for assignment and called up righthander Hector Ambriz.

Ambriz is 1-1 in Oklahoma City this season with two saves in 33 appearances.

Ambriz, 28, has 18 strikeouts in 24 1/3 innings with OKC.

Galarraga was 0-4 in five starts for the Astros with a 6.75 ERA.

Interim manager Tony DeFrancesco said no decision has been made on who replaces Galarraga in the rotation. The team is off on Monday.

Ambriz was signed by the Astros as a minor league free-agent on June 21. The 6-foot-2, 235 pound right-hander previously pitched in 20 games this season with the Triple-A Columbus Clippers as a member of the Cleveland Indians organization.

Ambriz, appeared in 34 games with the Cleveland Indians in 2010. The former 2006 fifth-round pick of the Arizona Diamondbacks, Ambriz was acquired by the Indians in the 2009 Rule 5 Draft.